Simultaneous catalytic cracking and desulfurization of hydrocarbons



' 'aremdrb. 8. 1949? 1 9" v Y f ,SIMULTANEOUS" CATALYTIC oaacxmc AND,DESULFUBIZATION or HYDRO-.

cannons I Milton M. Marisic, Woodbury,. and Arthur C.- Schmitt,.Wenonah, N. J., and Frederick 0. Frank, "Philadelphia, Pa., assignorsto Socon'y- Vacuum Oil Company ration of New York Incorporated, a corpoNo Drawing. Application June 10, 1944, Serial No. 539,790

.4 Claims. (Cl. 196-52) This invention relates to a novel catalyst forconversion of hydrocarbon oil and to processes of convertinghydrocarbons by contactingvapors thereof at conversion conditions oftemperature and pressure with the catalyst of this invention.

Plural oxide gels of silica containing minor proportions of oxides likeA1203, ZiOz, T1102, BeO and the like, are excellent hydrocarbonconversion catalysts. These catalysts are especially suitable foraccelerating the cracking of heavy fractions of petroleum to producehydrocarbons boiling in the gasoline range and to reform lighterpetroleum fractions, such as naphtha, so as to increase the rate offormation of high anti-knock motor fuel. In the destructivehydrogenation of thorium, beryllium and other difllcultly reduciblemetal oxides. Alternatively, the metal may be supplied in the silicatesolution, e. g as sodium aluminate. The solutions are mixed under suchcarbonaceous materials, such as middle oils,

paraflin-base gas oils, etc., the gel catalysts noted above are mostefficient at pressures ranging from 300 to 1000 atmospheres. Commercialequipment capable of withstanding such high pressures is extremelycostly, and for this reason, these catalysts have not been used in suchprocesses. Modification of the plural oxide gel catalysts according tothe method of this invention, by inclusion of oxides of iron, permitseconomic operation of destructive hydrogenation processes at pressuresas low as atmospheres; however, considerably higher-pressures may beused as, for example, 250 atmospheres, or above. Temperatures employedrange from about 700 F. to about 1000. preferably 800 to 900 F.

The iron-containing gel catalysts of this invention have been found tobe especially effective in the simultaneous cracking and desulfurizationof petroleum hydrocarbons containing organic sulfur compounds atoperating conditions generally employed in catalytic cracking. Thesegels function solely as desulfurization catalysts at temperatures lowerthan those used in catalytic cracking, say, below 800 F., preferably 500to 750 F. In industry, bauxite is employed as a desulfurizationcatalyst;however, its efficiency for this purpose is not as high as that of thepresent gel catalyst Furthermore, bauxite has practically' no activityas a cracking catalyst.

The plural oxide gels of this invention are formed by mixing a sodiumsilicate solution of the proper concentration with an acid solutioncontaining an acid a id an iron salt, together with one or more solublesalts of aluminum, zirconium,

conditions that a hydrosol forms without substantial precipitation andthat this hydrosol will have apH between 2.5 and 10, and preferablybetween pH 5 and 8.5. After a short period of time,as for example ,a fewseconds, a few minutes or longer, but preferably in less than minutes,the hydrosol should set to a gel. The gel thus formed is defined as ahydrogel. This hydrogel is washed, dried and heat treated according toconventional methods.

' EXAMPLE I SILICA, FERRIC OXIDE, ALUMINA GEL 94% SiOz, 3% FezOs, 3%A1203 (on dry basis) 6,720 cc. of sodium silicate containing 0.210 g.8102 per cc. (prepared by diluting N brand sodium silicate) was added toa well-agitated acid solution made up of 2245 cc. of 3.78 normal H01,1070 cc. of A12(SO4)3 containing 0.042 g. A1203 per cc., 889 cc. ofFeCl; solution containing 0.05 g. F9203 per cc., and 19 liters ofdistilled water. The resulting hydrosol set to a clear, firm gel in 25seconds, having a pH of 7.3.

Gel prepared according to the above directions has a total oxideconcentration, based on the weight of freshly formed hydrogel, of 5%,of-

which 94% 1s SiO2, 3% FezOa and 3% A1203.

The hydrogel thus obtained was broken up, par

tially dehydrated to of its original water content at 180 R, and washedfree of soluble salts by decantation with distilled water. It was thensubstantially freed of sodium ion by base exchanging for a suitableperiod of time in 5% ammonium chloride solution. The gel was finallywater washed free of chloride ions and dried, the temperature beinggradually raised to 1050 F'., at whichit was activated for five hours,prior to testing as a cracking catalyst.

' EXAMPLE II SILICA, FERRIC OXIDE, ALUMINA GEL SiOz, 3% F6203, 7%AlzOflon dry basis) 7,140 cc. of sodium silicate (of the sameconcentration used in Example I) was mixed with The hydrogel waspartially dried; washed and finally dried, as described in Example I.Analysis of the dried gel showed a sodium content of 0.02%.

EXAMIPIE m SILICA, Faaarc Oxrns, 111mm GEL 88.4% SiOz, 2.95% F6203, 6.9%A1203, 1.75% Naz fl (on dry basis) This gel was prepared exactly asdescribed in Example II, except that in the washing process, sodium ionswere not removed by base exchange with ammonium chloride.

Analysis of the dried gel tent of 1.3%.

showed a sodium con- EXAMPLE IV SILICA-ALUMINA IRON Oxma Gar. 96.5%SiOz, 3% A1203, 0.5% F8203 (on dry basis) This gel was prepared from thefollowing reagents according to the method described in ExampleI. FeCl:solution (0.03 g. F6203 per cc.) cc 300 A12(SO4)3 solution (0.042 g.A1203 per cc.)'

3.78 normal hydrochloric acid; cc 3400 Sodium silicate solution (0.210g. S10: per

cc.) cc 8280 Distilled water liters 16 This gel had a gelation time of75 seconds and a pH of 6.2.

EXAIVIPLE V SILICa-ALUMINA Iaon Qxrns Gal. 7 94.5% S102, 5% A1203, 0.5%F8203 (dry basis) The gel of this example was prepared from thefollowing reagents according to the method described in Example I.

The gelation time was 45 seconds, while the pH of the hydrosol was 7.2.

EXAMPLE VI SILICA-ALUMINA IRON x101: Gm. 92.5% 81.02, 7% A1203, 0.5%F8203 (on dry basis) The gel in this instance was prepared from thefollowing reagents according to the method described in Example I.

FeCls solution (0.05 g. F6203 per cc.) cc 120 3.78 normal hydrochloricacid cc 1140 A12(SO4)1 solution (0.042 g. A1203 per cc.)

. cc 2000 Sodium silicate solution (0.210 g. S101 per cc.) cc- 5285Distilled water liters-- 21 4 The gelation time was 40 seconds, whilethe DB of the hydrosol was 8.

EXAMPLE v11 SILICA-ALUMINA Icon Oxmr: Gn.

92% S'ZOz. 5% A1201, 3% mo: (on dry basis) The gel was prepared from thefollowing reagents according to the method described in Example I.

FeCh solution (0.05 g. F6203 per cc.) cc 3.78 normal hydrochloric acidcc Alz(SO4)a solution (0.042 g. A1203 per cc.)

Sodium silicate solution (0.210 g. S: per cc.) cc Distilled water liters14 The gelation time was 80 seconds, while the pH of the hydrosol was7.1.

The catalysts described in the above examples were tested in thecracking of a fraction of Oklahoma City gas oil having a boiling rangefrom 470 F. to 708 F. The oil vapors were conducted through the catalystbed at 800 F. and at a liquid space velocity of 1.5 for -minute periodsbetween regenerations. The cracking activity of these catalysts is shownin Table 1. Cracking activity is defined as the volume per centconversion of the oil charged to 410 F. endpoint gasoline.

TABLE 1 Catalyst Composition (on dry basis) Per cent F920:

Per cent Per cent velocity of 1.5 for 20-minute periods betweenregenerations. Data for the cracking activity and the desulfurizationefliciency are presented in Table 2: TABLE 2 Pcemm VOL Percent WeightSulfur Catalyst oi l to 410 F. Example E. P. (3850- in Gasoin Recyclenefmoval line line Stock g 25 0.22 1.15 62.5 as 0.25 1.13 114.3 11 0. as1.11 51.2 30 0.18 1.24 59.8 45 0.14 1.21 62.0 42 0.11 1.21 04.3 a 0.131.02 71.5

It is to be noted in Table 2 that catalysts V and VI, which are best ascracking catalysts for this oil. are also good desulfurizationcatalysts. Increasing the iron oxide content of catalyst V to 3% asexemplified by catalyst VII, reduces the cracking activity but improvesthe desulfurization eillciency. Increase in iron oxide content access:

alyst chamber at 810 F. and at a liquid space of catalyst VI to 3% asshown by catalyst II has no effect on the total desulfurization butreduces the extent of cracking. Therefore, for

processes requiring simultaneous cracking and resulfurization, catalystsV and VI are preferred over catalysts II and VII;

however, the latter catalysts would be better when only desulfurizationis desired. For, in this case, the cracking capacity of catalysts II andVII could be eliminated by a smaller lowering in temperature than wouldbe necessary with catalysts V and VI.

Table 3 compares the desulfurization efliciency of bauxite and thecatalysts of Example IV employing Slaughter-Duggan gas oil previouslydescribed. The desulfurizations were conducted at a liquid spacevelocity ods between regenerations at of 1.2 for one-hour perithetemperatures noted below. Steam and CO2 were used to aid in thevaporization and in the m aintenance of the charge oil in the vaporstate.

TABLE 3 Per Cent Wt. Catalyst T al?" Entrainer 32x23 Oil Bauxite....1.40 Example I 0. 75 auxite 1.28 Example IV... 1.01 Bauxite 1. 10Example IV 1.03 Example IV 0. 75

Liquid space velocity=0.5; time of run=1 hour.

Preferably, the catalyst contains about '75 to 97% SiO-i, 0.05 toducible oxide) and 0.2 to

A composite batch of the c in Examples II and VII was ity in promotingboth the A1203 (or other diflicultly re- F6203 (by weight).

atalysts described tested for activdestructive hydrogenation andcracking of a fraction of Oklahoma City gas oil, having a boiling to 708F.' Experiments were similar conditions so as results. The oil vaporsthe catalyst bed at 810 were C range from 470 carried out under toprovide comparable onducted through Rand at a liquid space velocity of1.5 for one-hour periods between regenerations. The results aresummarized in Table 4.

TABLE 4 Per Cent Vol. Per Cent Per Cent Conversion to Wt. Coke Vol. Liq.0 F. E. P. Gaso. Formed Recovery Cracking Conditions 23 (28%olefins).... 6.4 84

(Atmos. PL). Destructive Hydro- 36 (9% o1efins). 3.4 91

genation (20 Atm. of H: Pr.).

It is to be noted that destructive hydrogenation conditions increaseboth conversion. while at the same t mation is reduced. The olefin therecovery and irne, the coke forcontent of the re- 'desulfurization of. ahigh troleum hydrocarbon stock, which includes the step of contactingvapors of said stock, in the ab sence of hydrogen, at catalytic crackingconditions of temperature and pressure with a threecomponent driedsynthetic gel type catalyst consisting of about 94.5 per cent silica,about 5 per cent alumina and about 0.5 of ferric oxide.

3. A process for simultaneous cracking and desulfurization of a highsulfur-content petroleum hydrocarbon stock, which includes the step ofcontacting vapors of said stock, in the absenceof hydrogen, at catalyticcracking conditions of temperature and pressure with a threecomponentdried synthetic gel type catalyst consisting of about 92.5 per centsilica, about 7 per cent alumina and about 0.5 per cent by weight offerric oxide. I

per cent by weight 4. A process for simultaneous cracking anddesulfurization of a high sulfur-content petroleum hydrocarbon stock,which includes the step of contacting vapors of said stock, in theabsence of hydrogen, at catalytic cracking conditions of temperature andpressure with a threecomponent dried synthetic gel type catalystconsisting of about 96.5

cent alumina and about 0.5 per cent by weight of ferric oxide.

MILTON M. MABISIC. ARTHUR C. SCHMI'I'I. FREDERICK C. FRANK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PA'I'EN'IS Number Name Date 2,121,046 Pew, Jr June 21,1938 2,126,503 Retailliau et al Aug. 9, 1938 2,324,066 Connolly July 13,1943 2,347,216 Peterkin Apr. 25, 1944 2,348,576 Seguy May 9, 19442,355,388 Michael et al Aug. 8, 1944 FOREIGN PA'I'ENTS Number CountryDate a Great Britain Apr. 24, 1939 per cent silica, about 3 per.

Certificate of Correction Patent No. 2,461,069. I I February 8, 1949.

MILTON M. MARISIC ET AL.

It is hereby certified that errors appear in the printed specificationof the above numbered patent requiring correction as follows:

Column 2, line 24, Example 1, before the word containing insertsolution; column 5, line 5, for resulfurization read desulfunzat'ion;

and that the said Letters Patent should be read with these correctionstherein that the same may conform to the record of the case in thePatent Office.

Signed and sealed this 28th day of June, A. D. 1949.

[SEAL] THOMAS F. MURPHY,

Assistant Commissioner 0 f Patents.

